Search results

The instability and deflection of the thin-wall causes difficulty for control of the machining condition, affecting the accuracy of the modeling and simulation of the process.
; );,();,,( ↑↑=↑= = = ZAF ZPAVAQF thatsuchL L (1) where F is the tool-force, Q represents the volume of material removal and is a function of A, V and other relevant parameters, A is the contact area between the blank material and the cutter and is a function of the depth of cut Z and other factors, and V is the force-vector.
Each bi-arc curve segment bears the properties of Hermite splines that it connects two end points continuously and controls the curvature of the curve via two vectors originated at the end points.
[15] Iwabe H., Shimada T. and Yokoyama K., "Study on machining accuracy of thin wall work piece by end mill (analysis of deflection of work piece and tool due to cutting force and machining accuracy)", Nippon Kikai Gakkai Ronbunshu, C Hen Transactions of the Japan Society of Mechanical Engineers, Part C., Vol. 63 No. 605, January 1997, pp. 239-246.

Introduction The crack tip plastic zone size and shape are affected by the loading, elastic-plastic material properties and the level of strain constraint given by the specimen geometry and its thickness.
The method based on hardness measurement is possible due to the change of elastic-plastic properties during intense plastic cycling.
In addition, a simplified 2D numerical simulation of stress and strain fields around the crack tip will be performed with macroscopically homogeneous material properties.
The constant amplitude loading was decreasing gradually so that the stress intensity factor range was kept constant at ∆K=20 MPa m12 with the stress ratio R=0.1.
Therefore, the finite element mesh had to be built, input material properties and boundary conditions had to be specified.

It was found that both the residual stress and the hardness were strongly affected by the coating deposition conditions.
Thus, the RS becomes a limiting factor in feasible coating thickness.
Lastly, RS in PVD coatings can affect fatigue life of coated components [5,6,7].
In our experimental program, UMS TiN coatings deposited at different bias and pressure conditions were assessed for RS magnitude and anisotropy, as well as mechanical properties such as hardness and Young's modulus.
Post-deposition thermal treatment may be used to stabilize TiN coating properties in applications where coatings are exposed to elevated temperatures.

Steel corrosion is very aggressive as compared to other metals when it is exposed to atmosphere, where major factors causes corrosion of steel are variation of temperature, time of wetness, sulphur dioxide (SO2), carbon dioxide (CO2) and chloride pollution.
Atmospheric corrosion of metal is generally caused due to various factors like Rh, Rain, pH, [H+], SO2, HNO3, Cl-, TOW and their interactive factors which is very complex and difficult to quantify, and this phenomena occurs worldwide but depends on the concentration of atmospheric pollutants.
Ashrafizadeh, Effect of microstructure and texture on formability and mechanical properties of hot-dip galvanized steel sheets, J.
Ordine, Anticorrosive Properties of Hot-Dip Galvanized Weathering Steel in Atmospheric Exposure, Mater.
Rojas, Study on the effect of atmospheric corrosion on mechanical properties with impact test: Carbon steel and Galvanized steel, Mater.

It does not matter whether suspension has linear or nonlinear properties because the system has to be calibrated for the particular type of vehicle.
The faults in suspension affects the acceleration signals.
However, it should be remembered that in some cases the excitations may affect acceleration signals as if suspension is in damaged state.
The response of the vibrating mechanical system depends strongly on the level of excitations (track irregularities, velocity).
According to Fig. 9 - 12 the RMS and crest factor values do not provide clear information on suspension condition.

Whilst detailed characterisation of the properties of these nanostructured ceramics is still underway, preliminary results have suggested that neither the hardness or toughness has been improved compared to conventional, submicron-sized 3-YSZ.
Introduction Nanostructured materials have received much attention in recent years; their appeal is their potential to display unusual physical and mechanical properties such as superplasticity in ceramics at elevated temperatures, transparency for usually opaque materials, controlled band gaps in electronic materials, very high magnetoresistance and superparamagnetic properties, and higher hardness and strength in both metals and ceramics [1].
Successful approaches that have been developed include: The addition of solutes or 2 nd phase particles that reduce grain boundary mobilities or pin them; however this is limited to additives that do not negatively affect the desired properties of the final product [9,10] and so is a major limitation for many ceramic systems.
Although characterisation of the resultant ceramic properties has only just begun, preliminary results are somewhat disappointing.
[13] British Standards, 'Advanced Technical Ceramics - Monolithic Ceramics - General Textural Properties' Part 3, p 10, BS EN 623-3 (2001)

In these assemblies the stress field is complex, we have to consider the effect of the geometrical discontinuity, the contact, the tightening, the material properties and the applied load.
Fretting is the degradation of near-surface material that arises from a tripartite interaction among wear, corrosion and fatigue phenomena[2], often observed in nominally-clamped mechanical assemblies subjected to oscillatory loads or vibratory excitation.
In this case, the initiation of the fretting fatigue crack is affected by a lot of factors, such as the shear stresses τrθ, the contact normal force, the contact friction, etc, but the mechanism of the fretting fatigue damage is not clear and attracts a lot of researchers, which will be discussed below.
But such increase of the fretting fatigue life is not distinct, because the fretting fatigue is also affected by the contacting pressure, which accelerates the surface damage of the fretting fatigue.
Normally, the second factor is more important than the first.

In addition, the rivers of Taiwan flow down steep slopes with rapid currents, and the flow is extremely turbulent in particular segments of the rivers, causing pile scours that affect the stability of bridges in the area.
(4) Select any structural performance point according to the lateral pushover capacity spectrum and use nonflexible pseudo-spectral displacement and pseudo-spectral acceleration as labels, and then calculate the viscous damping ratio using ATC-40 to obtain a valid viscous damping ratio: (5) (5) The damping ratio varies from the 5% correction factor.
Furthermore, the spectral reduction factor can be calculated, and the capacity spectrum can be established according to the capacity curve.
Conclusion This study obtained the mechanical properties of the scour phenomenon of bridge piers by considering the characteristics of stagnation points and separation points of fluid mechanics, as well as the theory of turbulent flow.

Due to the flow behavior of molten metal is affected by the back pressure of mold residual air in high pressure die casting (HPDC) process, the back pressure conditions should be considered in order to simulate the HPDC process precisely.
Gas porosity is one of the most important defects that reduce thermal and mechanical properties such as yield strength, ductility and modulus of elasticity of parts produced in the pressure die casting.
The factors which generate the gas porosity were analyzed.

Blind Separation Of Coherent Signals Based On Toeplitz Matrix Reconstruction Ling Tang1, a, Hong Song1,b and Lianjun Hu2,c 1Automation and electronic information college, Sichuan University Of Science & Engineering, Zigong, China 2School of mechanical engineering college, Sichuan University Of Science & Engineering, Zigong, China afashion-kitty@163.com, bsh8887878@sina.com, cHLj28288@sina.com Keywords: blind separation, coherent signals, Toeplitz matrix, direction-of-arrival, beamforming Abstract.
But in reality, due to finite snapshots and system deviation, and the presence of coherent sources, the Toeplitz property of covariance matrix R is damaged, generally matrix is diagonally dominant, which thus affects the performance of DOA based on covariance matrix decomposition.
Experiment 1 DOA estimation of coherent sources using Toeplitz matrix reconstruction algorithm Assuse five coherent sources arriving from , the corresponding fading factor margin is , signal to noise ratio are 20dB, 512 snapshots, and 200 times Monte-Carlo experiment.
Experiment 2 Testing separation performance of each source Consider three coherent sources arriving from, the corresponding fading factor margin is , signal to noise ratio are 20dB, 512 snapshots.
Experiment3 Relationship of output SINR and input SNR Assuse three coherent sources arriving from -400, 100, 200, the corresponding fading factor margin is , 512 snapshots.